Narrated ‘Aisha: Allah’s Apostle said, “Search for the Night of Qadr in the odd nights of the last ten days of Ramadan.”

(Sahih Bukhari)

Narrated ‘Aisha: Allah’s Apostle used to practice Itikaf in the last ten nights of Ramadan and used to say, “Look for the Night of Qadr in the last ten nights of the month of Ramadan ,”

(Sahih Bukhari)

Narrated Aisha: With the start of the last ten days of Ramadan, the Prophet used to tighten his waist belt (i.e. work hard) and used to pray all the night, and used to keep his family awake for the prayers.